From: Amir Goldstein <amir73il@gmail.com> mainline inclusion from mainline-5.13-rc1 commit 59cda49ecf6c9a32fae4942420701b6e087204f6 category: feature bugzilla: 187162, https://gitee.com/openeuler/kernel/issues/I5FYKV CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ------------------------------------------------- Since kernel v5.1, fanotify_init(2) supports the flag FAN_REPORT_FID for identifying objects using file handle and fsid in events. fanotify_mark(2) fails with -ENODEV when trying to set a mark on filesystems that report null f_fsid in stasfs(2). Use the digest of uuid as f_fsid for tmpfs to uniquely identify tmpfs objects as best as possible and allow setting an fanotify mark that reports events with file handles on tmpfs. Link: https://lore.kernel.org/r/20210322173944.449469-3-amir73il@gmail.com Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- mm/shmem.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/shmem.c b/mm/shmem.c index 9df016296347..201086030e72 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2869,6 +2869,9 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_ffree = sbinfo->free_inodes; } /* else leave those fields 0 like simple_statfs */ + + buf->f_fsid = uuid_to_fsid(dentry->d_sb->s_uuid.b); + return 0; } -- 2.20.1